JP3513782B2 - Aqueous resin dispersion - Google Patents

Description

Detailed Description of the Invention

The present invention relates to an aqueous resin dispersion, more specifically, it has excellent adhesion to a substrate and stability, exhibits excellent vibration damping properties over a wide temperature range, and is flexible, chipping-resistant and low-temperature. Can form a film with excellent impact resistance,
Particularly, it relates to an aqueous resin dispersion liquid which is useful for producing an aqueous coating composition.

Conventionally, in order to prevent vibration and noise on the surface of structural members such as vehicles, ships, various machines and instruments, building materials, etc., in order to thicken the members themselves or reduce the occurrence of vibrations. Various measures have been taken to prevent vibration and noise, such as attempting to improve the device itself, attaching a sheet-shaped damping material to the surface of the member, and applying or spraying a damping coating material.

However, making the member itself thick causes problems such as cost increase of the member and deterioration of workability, and further leads to increase of fuel consumption in the case of automobiles and the like. In addition, when the sheet-shaped vibration damping material is attached, it is indispensable to perform a cutting process according to the shape of the member, which is a problem in that the process is complicated.

Further, various types of damping paints have been proposed in the past, for example, those based on materials having viscoelastic properties such as rubber, asphalt, various synthetic resin emulsions, and the like. It is known to further add inorganic powders such as graphite, mica, hirucite, calcium carbonate, talc and clay to impart mechanical hysteresis and internal friction.

However, most of these conventionally proposed damping paints exhibit high damping properties, but have a narrow temperature range exhibiting the high damping properties, and the coating film formed is hard and brittle. However, there are drawbacks such as poor chipping resistance.

On the other hand, the water-based vibration-damping paint has been attracting attention because it is superior in terms of easiness of handling and safety of working environment.
There is a problem that it is generally not easy to form a thick coating film.

From the standpoint of exhibiting its performance, the vibration-damping paint must normally form a thick coating film of 1000 μm or more, and from the viewpoint of productivity, it is strongly desired that it be rapidly dried at a high temperature. However, when a thick coating film is heated rapidly, the surface of the coating film dries first to form an epidermis, and then the water remaining inside evaporates and lifts the epidermis formed earlier and blister (heat blister). There is a problem such as the occurrence of cracks and the breakage of the epidermis, resulting in cracks. To avoid the generation of blisters and crevices, if a thick coating film is dried at room temperature, the film formation will be insufficient and the stress during drying will not be relieved by heat, causing problems such as cracking of the coating film. Occurs.

Further, as an aqueous vibration damping paint exhibiting excellent vibration damping performance in a wide temperature range from low temperature to high temperature, emulsion type styrene-acrylic acid ester copolymer, polyamide epoxy compound and / or melamine-formaldehyde compound and An aqueous vibration-damping paint (Japanese Patent Publication No. 63-24550) obtained by dispersing a scale-like inorganic powder in water, an emulsion-type styrene-acrylic acid ester copolymer,
A water-based vibration-damping paint prepared by dispersing an emulsion vinyl acetate polymer, a cross-linking agent, and scale-like inorganic powder in water.
No. 33747), but coatings formed from these coatings have insufficient flexibility and are not satisfactory in terms of low temperature physical properties such as chipping resistance and low temperature impact resistance. Is.

The main object of the present invention is to form a film which exhibits excellent vibration damping performance in a wide temperature range from low temperature to high temperature, and is flexible and has excellent chipping resistance and low temperature impact resistance. It is another object of the present invention to provide an aqueous resin dispersion which is excellent in adhesion to a substrate, storage stability, mechanical stability and the like.

Other objects and features of the invention will be apparent from the following description.

According to the present invention, an aqueous resin dispersion liquid containing polymer fine particles dispersed in an aqueous medium,
The polymer fine particles are (A) glass transition temperature (Tg _A-1 ).
Is in the range of −10 ° C. to 50 ° C., and a glass transition temperature (Tg _A-2 ) covering the core and a core made of a carboxyl group-containing acrylic polymer (A-1) is −10 ° C. A core-shell type composite fine particle consisting of a shell portion composed of a low polymer (A-2), wherein the core portion occupies 50 to 90% by weight, and the balance is The fine composite particles that are the shell portion, and (B) the glass transition temperature (Tg
_B-1 ) is in the range of -10 ° C to 50 ° C and is at least 10 ° C higher than the glass transition temperature (Tg _A-1 ) of the polymer (A-1) at the core of the composite fine particles (A). A core portion made of a low acrylic polymer (B-1), and a shell portion made of a polymer (B-2) having a glass transition temperature (Tg _B-2 ) lower than -10 ° C for coating the core portion. The core-shell type composite fine particles, wherein the core portion is 5 based on the weight of the composite fine particles.
Composite fine particles occupying 0 to 90 parts by weight and the rest being shells and / or (C) having a glass transition temperature (Tg _c ) of -3.
It is in the range of 0 ° C to 50 ° C and the glass transition temperature (T of the polymer (A-1) at the core of the composite fine particles (A) (T
g _{A- 1} ) and polymer fine particles different from each other by at least 10 ° C., based on the total amount of the fine particles (A), (B) and (C), 30 to 90% by weight of the composite fine particles (A), And the total amount of the composite fine particles (B) and the polymer fine particles (C) is 70
An aqueous resin dispersion containing 10 to 10% by weight is provided.

The aqueous resin dispersion of the present invention comprises an aqueous medium,
Consisting essentially of polymer particles stably dispersed therein, and the polymer particles comprising certain specific cores.
What has a great feature in that the shell-type composite particles (A) are combined with other specific core-shell-type composite particles (B) and / or polymer fine particles (C) having a specific glass transition temperature The coating film formed therefrom exhibits excellent vibration damping performance with a loss factor (tan δ) of 0.03 or more over a wide temperature range of about 0 to about 60 ° C., and at room temperature. It has the remarkable characteristics that it is also excellent in chipping resistance and impact resistance in a low temperature atmosphere.

The aqueous resin dispersion of the present invention will be described in more detail below.

Core-shell type composite fine particles (A) The fine composite particles (A) contained as an essential polymer fine particle component in the aqueous resin dispersion of the present invention are (1) glass transition temperature (Tg _A-1 ). Of a carboxyl group-containing acrylic polymer (A-1) having a temperature of −10 ° C. to 50 ° C., and (2) a glass transition temperature (T
g _A-2 ) is a core-shell type composite fine particle consisting of a shell portion made of a polymer ( _A-2 ) having a temperature lower than −10 ° C., wherein the core portion is based on the weight of the composite fine particle. 50-90% by weight
And the rest is the shell.

Acrylic polymer containing a carboxyl group (A
-1): The acrylic polymer (A-1) forming the core of the composite fine particles (A) contains a carboxyl group, and its content is not strictly limited. It can be varied over a wide range depending on the ease of emulsion polymerization, the properties desired for the final aqueous resin dispersion, and the like. Generally, the acrylic polymer (A-1) 100
2.5-100 milligram equivalents per g, preferably 5
Conveniently, it is in the range of 90 milliequivalents, more preferably 10 to 80 milliequivalents, and the carboxyl group content of the acrylic polymer (A-1) is
It is desirable that the total content of carboxyl groups in the fine composite particles (A) is at least 50% by weight, preferably 70% by weight or more, and more preferably 80% by weight or more.

Further, it is important that the glass transition temperature (Tg _A-1 ) of the acrylic polymer (A _-1 ) is within the range of -10 ° C to 50 ° C. If the Tg _{A-1 of} the acrylic polymer (A-1) constituting the core of the composite fine particles (A) is lower than -10 ° C, the vibration damping performance of the resulting coating at room temperature is insufficient. In addition, the chipping resistance at room temperature, the adhesion to the surface of the base material, the water resistance, etc. tend to be insufficient.
If the temperature is higher than 0 ° C, the vibration damping performance at room temperature tends to be inadequate, and the room temperature chipping resistance and low temperature impact resistance tend to decrease. Therefore, Tg _A-1 is preferably in the range of −5 ° C. to 45 ° C., more preferably −0 ° C. to 40 ° C.

Further, the molecular weight of the acrylic polymer (A-1) is not particularly limited, but it can usually have a weight average molecular weight of 500,000 or more, preferably 1,000,000 or more.

As long as the acrylic polymer (A-1) has the above-mentioned characteristics, the kind of the monomer constituting the polymer is not strictly limited, but it is usually described below (M-1). , (M-2) and (M-3) are preferably acrylic copolymers formed by copolymerizing the three monomers so as to satisfy the carboxyl group content and Tg.

Equation (M-1)

[0020]

[Chemical 5]

In the formula, R ¹ represents a hydrogen atom or a methyl group, and R ² represents a linear or branched alkyl group having 1 to 12 carbon atoms, preferably 1 to 9 carbon atoms. (Meth) acrylic acid alkyl ester: for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth)
Acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth)
Acrylate, nonyl acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, t-dodecyl (meth) acrylate and the like. Among these, particularly preferable are:
Examples thereof include methyl methacrylate, ethyl acrylate, butyl acrylate, octyl acrylate, 2-ethylhexyl acrylate and isononyl acrylate.

(M-2) α, β-unsaturated mono- or di-carboxylic acid having 3 to 5 carbon atoms: for example, acrylic acid, methacrylic acid, crotonic acid, citraconic acid, itaconic acid, maleic acid, maleic anhydride. Acid, fumaric acid, etc. Among these, acrylic acid, methacrylic acid and itaconic acid are particularly preferable.

Formula (M-3)

[0024]

[Chemical 6]

In the formula, R ³ represents a hydrogen atom or a methyl group, X represents a hydrogen atom, a methyl group, an ethyl group, a vinyl group, a mono- or di-dihalovinyl group, and an aryl group having 6 to 8 carbon atoms (eg, Phenyl, tolyl, ethylphenyl,
(Xylyl, etc.), a nitrile group or a —OCOR ⁴ group, wherein R ⁴ represents a hydrogen atom or a straight chain or branched chain alkyl group having 1 to 12 carbon atoms. ) Monomer copolymerizable with (meth) acrylic acid alkyl ester: vinyl aromatic compounds such as styrene, α-methylstyrene, vinyltoluene, ethylvinylbenzene; acrylonitrile, methacrylonitrile; vinyl formate, vinyl acetate, Vinyl esters such as vinyl propionate and vinyl versatate (trade name); monoolefins such as ethylene, propylene, butylene and isobutylene; conjugated diolephins such as butadiene, isoprene and chloroprene. Among these, preferred are those in which X in the above formula (II) represents a phenyl group or a nitrile group, particularly styrene and acrylonitrile.

The copolymerization ratio of the above-mentioned monomers is preferably within the following range based on the total amount of the monomers as the charged amount at the time of polymerization of the acrylic polymer (A-1).

Monomer (M-1): Generally 40-99.
5% by weight, preferably 45 to 99% by weight, more preferably 50 to 98% by weight; Monomer (M-2): generally 0.5 to 20% by weight, preferably 0.8 to 15% by weight, more preferably 1-10
% By weight; Monomer (M-3): generally 0-59.5% by weight, preferably 0-54% by weight, more preferably 0-48% by weight.

[0028] Polymer (A-2): The polymer constituting the shell portion of the composite fine particles (A) in the present invention (A-2), the glass transition temperature (Tg _A-2) is -10 ° C. The lower one is used. If Tg _A-2 is too high, such as −10 ° C. or higher, cold resistance and flexibility of the obtained coating tend to be lost, and particularly low temperature impact resistance tends to be lowered. Thus, the glass transition temperature Tg _A-2 of the polymer (A-2) constituting the shell is generally -15 ° C to -60 ° C, especially -20 ° C.
It is desirable to be in the range of ℃ to -50 ℃.

The polymer (A-2) is generally 500,
It can have a weight average molecular weight of, 000,000 or more, preferably 1,000,000 or more.

The type of the polymer (A-2) is not particularly limited, and various thermoplastic resins can be used as the polymer (A-2), but generally, an acrylic polymer and A urethane polymer, particularly the former acrylic polymer, is preferable. These will be described more specifically below.

The acrylic polymer (A-2-1) usable as the shell polymer (A-2) has a Tg of the above Tg.
_The composition of the monomer constituting the polymer is not particularly limited as long as it is within the range of _A-2 , but for example, at least one kind of the above-mentioned monomer (M-1) is used as an essential component, Accordingly, an acrylic (co) polymer obtained by combining (co) polymerizing one or more kinds of monomers selected from the monomers (M-2) and (M-3) is preferable.

Thus, the acrylic polymer (A-2-
Suitable examples of the monomer component constituting 1) include, as the monomer (M-1), a C _1-9 alkyl ester of (meth) acrylic acid represented by methyl methacrylate, butyl acrylate and 2-ethylhexyl acrylate; Examples of (M-2) include acrylic acid or methacrylic acid; and examples of the monomer (M-3) include a combination of styrene and vinyl versatate (trade name).

The acrylic polymer (A-2-1)
However, when the monomer (M-2) is contained as a constituent monomer component, the content of the monomer (M-2) in the polymer (A-2-1) is not limited to that of the polymers (A-1) and (A-2- It is desirable that the amount is 50% by weight or less, preferably 30% by weight or less, and more preferably 20% by weight or less based on the total amount of the monomers (M-2) in 1).

The composition ratio of the monomers constituting the acrylic polymer (A-2-1) is such that the acrylic polymer (A-2-
The charged amount at the time of polymerization of 1) is preferably within the following range based on the total amount of monomers.

Monomer (M-1): Generally 50 to 100
% By weight, preferably 70-100% by weight; Monomer (M-2): generally 0-10% by weight, preferably 0-5% by weight; Monomer (M-3): generally 0-50% by weight, preferably 0 ~ 30% by weight.

On the other hand, the urethane polymer (A-2-2) which can be used as the polymer (A-2) can be one usually used in the fields of coating materials, adhesives and the like.

Such urethane polymer (A-2-2)
Can be prepared by reacting a urethane prepolymer having an isocyanate group at the terminal obtained from a polyisocyanate compound and a polyol compound with a chain extender according to a usual method.

As the polyisocyanate compound which can be used in the production of the urethane polymer (A-2-2),
For example, 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate,
Aromatic polyisocyanate compounds such as 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate and 1,3-xylylene diisocyanate; 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4-trimethyl-
Aliphatic polyisocyanate compounds such as 1,6-hexamethylene diisocyanate, 1,8-octamethylene diisocyanate, 1,10-decamethylene diisocyanate;
Such as 1,3- or 1,4-cyclohexylene diisocyanate, 1-methylcyclohexane-1,3- or 1,4-diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,3-isocyanate methylcyclohexane Alicyclic polyisocyanate compound; and the like. Among these polyisocyanate compounds, preferred are, for example, 2,4- or 2,6-tolylene diisocyanate,
Examples include 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, and isophorone diisocyanate.

Polyol compounds which can be reacted with the above polyisocyanate compound include polyester polyols, polyether polyols and polyester ether polyols, and the polyol compounds include polyester polyols, polyether polyols and polyester ether polyols. and so on. Examples of polyester polyols include polyhydric alcohols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, glycerol, trimethylolpropane, pentaerythritol, sorbitan, and sorbitol, and amber, for example. Acids, adipic acid, sebacic acid, maleic acid, fumaric acid, mesaconic acid, citraconic acid, icotanic acid, glutaric acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid, trimellitic acid, dodecanedicarboxylic acid, etc. Examples thereof include condensates with carboxylic acids and lactone polymers. Examples of the above polyether polyols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol and polyethylene propylene glycol. Polyalkylene glycols such as Cole can be mentioned. As the polyester ether polyols, those obtained by adding an alkylene oxide such as ethylene oxide to the above polyester polyols, and the above polyether polyols and the above polycarboxylic acid are condensed. Examples thereof include those having a hydroxyl group at the terminal.

As the chain extender, a compound having at least two functional groups containing an active hydrogen atom reactive with an isocyanate group can be used, and typical examples thereof include water and polyhydric compounds. Examples include polyhydric alcohols, primary or secondary polyhydric amines, hydrazine and derivatives thereof.

Examples of the above polyhydric alcohols include:
Ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2- or 1,3-propylene glycol, 1,2-, 1,3- or 1,4-butylene glycol, 2,2-dimethyl-1, 3-
Propylene glycol, 1,6-hexanediol, 2,
Aliphatic diol such as 2,4-trimethyl-1,3-pentanediol; Alicyclic ring such as 2,2,4,4-tetramethylcyclobutanediol, 1,3-cyclopentanediol, methylenebis (4-cyclohexanol) Group diols; 1,4
-Phenylene bis (2-hydroxyethyl ether),
Aromatic diols such as 1,2-propylene glycol bis (2-hydroxyphenyl ether); and the like. Examples of polyvalent amines include ethylenediamine, hexamethylenediamine, isophoronediamine, diaminodiphenylmethane, and diethylenetriamine. Examples of hydrazine derivatives include dimethylhydrazine and 1,6-hexamethylenebis. Substituted hydrazine such as hydrazine; a reaction product of dicarboxylic acid, disulfonic acid, lactone or polyhydric alcohol and hydrazine; and the like.

Examples of the chain extender include, in addition to these, particularly those used for imparting ionicity to urethane prepolymers and urethane polymers when they are emulsified, and specific examples thereof are given. For example, dihydroxycarboxylic acid such as 2,2-dimethylolacetic acid, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolvaleric acid; 2,5-diaminobenzoic acid, α, ε -Caproic acid (lysine), 2-amino-5
-Diaminocarboxylic acids such as guanidinovaleric acid (arginine); alkyldialkanolamines such as methyldiethanolamine; and the like.

For the urethane prepolymer having an isocyanate group at the terminal, for example, the polyisocyanate compound and the polyol compound are used in a ratio such that the isocyanate group is equivalent to the hydroxyl group in excess, and the mixture is kept under a nitrogen atmosphere. 25-110 with stirring in an organic solvent
It can be produced by reacting at a temperature of ° C in the presence of a catalyst, if necessary.

Examples of the organic solvent which can be used here include ketones such as acetone and methyl ethyl ketone; ethers such as dioxane and tetrahydrofuran;
Examples thereof include esters such as ethyl acetate; aliphatic hydrocarbons such as heptane and octane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane. In addition, useful reaction catalysts include, for example, tertiary amines such as triethylamine; inorganic salts such as stannous chloride; di-n-
Organometallic compounds such as butyltin dilaurate; and the like.

The urethane prepolymer prepared as described above is reacted with a chain extender by a method known per se to give a urethane polymer (A-) suitable as a polymer (A-2) for the shell portion. 2-2) can be obtained.

Structure of Composite Fine Particles (A) The composite fine particles (A) are the above-mentioned acrylic polymer (A).
It is a composite fine particle having a core-shell structure comprising a core part consisting of -1) and a shell part consisting of the polymer (A-2). The core part can consist essentially of the above-mentioned carboxyl group-containing acrylic polymer (A-1), but in some cases, a small amount of the polymer (A-2) may be mixed. Further, the shell portion can be composed substantially only of the polymer (A-2), but in some cases, a small amount of the carboxyl group-containing acrylic polymer (A-1) is mixed. May be.

Therefore, the ratio of the core polymer (A-1) and the shell polymer (A-2) in the dispersed composite fine particles (A) depends on the properties desired in the final aqueous resin dispersion. The core polymer (A-1) is generally 50 to 90 based on the weight of the composite fine particles (A).
%, Preferably 60 to 85% by weight, more preferably 70 to 80% by weight, and the shell polymer (A
-2) can be in the range of 50 to 10% by weight, preferably 40 to 15% by weight, more preferably 30 to 20% by weight. The core polymer (A in the composite fine particles (A)
If the proportion of -1) is less than 50% by weight, the vibration-damping property of the formed film tends to be insufficient, and if it exceeds 90% by weight, the effect of the shell polymer (A-2) tends to be insufficient. It is difficult to appear, and the formed coating becomes too hard, and the low temperature impact resistance tends to decrease.

When the shell polymer (A-2) is the above-mentioned acrylic polymer (A-2-1), the core polymer (A-1) and the shell polymer (A It is desirable to select -2) so that the total monomer composition of the composite fine particles (A) is within the range shown below.

Monomer (M-1): Generally from 40 to 99.
5% by weight, preferably 45 to 99% by weight, more preferably 50 to 95% by weight; Monomer (M-2): generally 0.5 to 10% by weight, preferably 1 to 5% by weight; Monomer (M-3) ): Generally 0 to 60% by weight, preferably 0 to 55% by weight, more preferably 0 to 50% by weight.

The fine composite particles (A) in the aqueous resin dispersion of the present invention are composed of a core part made of the acrylic polymer (A-1) and a polymer (A-2) coating the core part. It is preferably composed of substantially spherical particles having a shell portion, and the average particle diameter of the particles is generally 0.05 to 5 microns, preferably 0.05 to 0.9 microns, and more preferably 0.1. It can be in the range of ~ 0.5 micron. The average particle size of the composite fine particles (A) and the composite fine particles (B) and polymer fine particles (C) described later is D.
It is a value measured by the LS method.

It is desirable that the shell part uniformly covers the surface layer part of the core part. However, in some cases, the shell part may be partly covered, for example, in a mesh shape or an island shape. it can. The composite fine particles (A) are acidic mainly due to the carboxyl group-containing acrylic polymer (A-1) constituting the core, and the content of the carboxyl groups in the particles is determined by the conductivity titration method. Measure, 100g of composite particles
It can usually be in the range of 5 to 150 milliequivalents, especially 10 to 75 milliequivalents.

The acrylic polymer (A-1) for the core part
The content of the carboxyl group can be measured by the conductivity titration method by sampling at the time when the formation of the emulsion of the core polymer (A-1) is finished in the production process of the aqueous dispersion.

When the shell polymer (A-2) is a urethane polymer (A-2-2), composite fine particles (A)
As described below, is usually prepared by adding an acrylic monomer that forms the core portion in the presence of an emulsion or an aqueous solution of a urethane polymer for forming a shell portion and polymerizing it. Part of acrylic polymer (A-
The content of the carboxyl group in 1) is determined by measuring the content of the carboxyl group of each of the urethane polymer and the composite fine particles to be produced by the above method, and by the following calculation formula, the acrylic polymer of the core part. The content of the carboxyl group of (A-1) can be determined.

[0054]

[Equation 1]

Here, X _A : Carboxyl group content of core acrylic polymer X _p : Carboxyl group content of composite fine particles X _u : Carboxyl group content of urethane polymer W _u : In composite fine particles Weight fraction of urethane polymer occupying in: W _A : Weight fraction of core acrylic polymer in the composite fine particles Aqueous medium : Composite fine particles (A) described above, and composite fine particles described later The aqueous medium as a dispersion medium for dispersing (B) and the polymer fine particles (C) is usually water, but in some cases, a mixed solvent of water and a water-miscible organic solvent is used. You can also

Preparation of Aqueous Dispersion of Composite Fine Particles (A) :
The aqueous dispersion of the composite fine particles (A) in the case where the shell polymer (A-2) is the acrylic polymer (A-2-1) as described above is a so-called "seed polymerization method" known per se. Can be prepared by a multistage emulsion polymerization method such as
For example, the aqueous dispersion is (1) in the presence of a surfactant and / or a protective colloid, in an aqueous medium, a monomer (A) in a proportion necessary to form the core polymer (A-1). M-1), (M-2) and (M-3) are emulsion polymerized to prepare an emulsion of the carboxyl group-containing acrylic polymer (A-1), and (2) the acrylic polymer formed. Monomers (M-1), (M-2) and (M) in proportions necessary to form the acrylic polymer (A-2-1) in the shell portion with respect to the emulsion of the polymer (A-1). −
It can be manufactured by a step of adding 3) in one step or multiple steps and further emulsion polymerization.

As the surfactant in the above step (1), any of nonionic, anionic, cationic and amphoteric surfactants can be used, but usually nonionic and / or anionic surfactants are used. Agents are preferred. Examples of anionic surfactants that can be used include fatty acid salts such as sodium stearate, sodium oleate, and sodium laurate; alkylaryl sulfonates such as sodium dodecylbenzenesulfonate; alkyl (or alkenyl) such as sodium lauryl sulfate. ) Sulfate ester salts; alkyl sulfosuccinate ester salts such as sodium monooctyl sulfosuccinate, sodium dioctyl sulfosuccinate, sodium polyoxyethylene lauryl sulfosuccinate and derivatives thereof; polyoxyalkylene alkyl (or sodium polyoxyethylene lauryl ether sulfate) (or Alkenyl) ether sulfate salts; polyoxyethylene nonylphenol ether sodium sulfate and other polyoxyalkylene alkyl aryls Like ether sulfate salts.

Examples of nonionic surfactants that can be used include polyoxyalkylene alkyl (or alkenyl) ethers such as polyoxyethylene lauryl ether and polyoxyethylene stearyl ether; polyoxyethylene octylphenol ether,
Polyoxyalkylene alkyl aryl ethers such as polyoxyethylene nonylphenol ether; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monostearate, sorbitan trioleate; polyoxyalkylene sorbitan fatty acids such as polyoxyethylene sorbitan monolaurate Esters; polyoxyalkylene fatty acid esters such as polyoxyethylene monolaurate and polyoxyethylene monostearate; glycerin fatty acid esters such as oleic acid monoglyceride and stearic acid monoglyceride; polyoxyethylene / polyoxypropylene block copolymers; Etc. can be illustrated.

Further, cationic surfactants that can be used include, for example, alkylamine salts such as laurylamine acetate; quaternary ammonium salts such as lauryltrimethylammonium chloride and alkylbenzyldimethylammonium chloride; polyoxyethyl. Examples thereof include alkylamines, and examples of the amphoteric surfactant include alkylbetaine such as laurylbetaine.

Furthermore, fluorine-containing surfactants in which a part of hydrogen atoms in the alkyl groups of these surfactants are replaced with fluorine, and radical copolymerizable unsaturated bonds in the molecular structures of these surfactants. It is also possible to use a so-called reactive surfactant or the like.

Among these surfactants, the nonionic surfactants are polyoxyalkylene alkyl (or alkenyl) ethers and polyoxyalkylene alkyls from the viewpoint of generation of agglomerates during emulsion polymerization. Aryl ethers; and, as anionic surfactants, alkyl aryl sulfonates, alkyl (or alkenyl) sulfates, alkyl sulfosuccinic acid ester salts and derivatives thereof, polyoxyalkylene alkyl (or alkenyl) ether sulfates, It is preferable to use polyoxyalkylene alkylaryl ether sulfate ester salts and the like. These surfactants may be used alone or in appropriate combination.

The amount of the above-mentioned surfactant used can be changed according to the kind of the surfactant and the kind of the monomer to be used, but in general, the core polymer (A-1) and the shell polymer ( A-2-1) to about 0.5 to about 10 parts by weight, preferably about 1 to about 6 parts by weight, more preferably about 1 to about 4 parts by weight, based on 100 parts by weight of the total amount of the monomers used to form A-2-1). It can be within the range of parts.

On the other hand, examples of the protective colloid that can be used in the step (1) include polyvinyl alcohols such as partially saponified polyvinyl alcohol, fully saponified polyvinyl alcohol and modified polyvinyl alcohol; hydroxyethyl cellulose, hydroxypropyl cellulose and carboxy. Cellulose derivatives such as methyl cellulose salts; natural polysaccharides such as guar gum and the like.

These protective colloids may be used alone or in combination with the above-mentioned surfactant. The amount used depends on the use conditions, but is usually the core polymer (A-
1) and the shell polymer (A-2-1) can be in the range of about 0 to about 3 parts by weight based on 100 parts by weight of the total amount of the monomers used to form the polymer.

Examples of the polymerization initiator that can be used in the emulsion polymerization in the step (1) include persulfates such as ammonium persulfate, potassium persulfate and sodium persulfate; t-
Examples thereof include organic peroxides such as butyl hydroperoxide, cumene hydroperoxide and p-menthane hydroperoxide; hydrogen peroxide; and the like, and these can be used alone or in combination of two or more.

The amount of the polymerization initiator used is not critical and can be appropriately selected, but in general, the core polymer (A-
100 total of monomers used to form 1)
About 0.05 to about 1 part by weight, more preferably about 0.1 to about 0.7 part by weight, particularly preferably about 0.1 to about 1 part by weight.
It can be exemplified within the range of about 0.5 parts by weight.

If desired, a reducing agent may be used in combination with the emulsion polymerization in the step (1). Examples of the reducing agent that can be used include reducing organic compounds such as ascorbic acid, tartaric acid, citric acid, and glucose; and reducing inorganic compounds such as sodium thiosulfate, sodium sulfite, sodium bisulfite, and sodium metabisulfite. It can be illustrated.

The amount of such a reducing agent used can also be appropriately selected, but it is usually about 0.10 parts by weight based on 100 parts by weight of the total amount of the monomers used for forming the core polymer (A-1). It can be exemplified in the range of 05 to about 1 part by weight.

Furthermore, a chain transfer agent can be optionally used in the emulsion polymerization in the step (1).
Examples of such chain transfer agents include cyanoacetic acid;
C _1-8 alkyl esters of cyanoacetic acid; bromoacetic acid;
C _1-8 alkyl esters of bromoacetic acid; aromatic compounds such as anthracene, phenanthrene, fluorene, 9-phenylfluorene; p-nitroaniline, nitrobenzene, dinitrobenzene, p-nitrobenzoic acid,
Aromatic nitro compounds such as p-nitrophenol and p-nitrotoluene; benzoquinone, benzoquinone derivatives such as 2,3,5,6-tetramethyl-p-benzoquinone;
Borane derivatives such as tributylborane; carbon tetrabromide, carbon tetrachloride, 1,1,2,2-tetrabromoethane, tribromoethylene, trichloroethylene, bromotrichloromethane, tribromomethane, 3-chloro-1-propene, etc. Halogenated hydrocarbons; aldehydes such as chloral and furaldehyde; alkyl mercaptans having 1 to 18 carbon atoms; aromatic mercaptans such as thiophenol and toluene mercaptan; mercaptoacetic acid; C _1-10 alkyl esters of mercaptoacetic acid A hydroxyalkyl mercaptan having 1 to 12 carbon atoms; a terpene such as binene and terpinolene.

When the above chain transfer agent is used, its amount is about 0.005 to about 3. 0 based on 100 parts by weight of the total amount of the monomers used to form the core polymer (A-1).
It is preferably within the range of 0 parts by weight.

As one preferable method for carrying out the step (1), the core polymer (A-1) is added to an aqueous medium optionally containing a surfactant and / or a protective colloid. The monomer component for forming a), a surfactant and / or a protective colloid, a polymerization initiator, and other components used as necessary are sequentially added.
The emulsion polymerization of step (1) can generally be carried out at a temperature of about 30 to about 100 ° C, preferably about 40 to about 90 ° C. Thereby, the emulsion of the carboxyl group-containing acrylic polymer (A-1) can be formed.

Then, in step (2), the shell polymer (A-2-1) for forming the shell polymer (A-2-1) is added to the emulsion of the core polymer (A-1) thus obtained. A monomer is added and emulsion polymerization is further performed. This second stage emulsion polymerization is carried out substantially without the addition of surfactants and / or protective colloids.

For example, the second-stage polymerization is carried out in the step (1)
In the emulsion of the core polymer (A-1) obtained in
A monomer component necessary for forming the acrylic polymer (A-2-1) of the shell part, a polymerization initiator, and other components used as necessary, for example, a reducing agent or a chain transfer agent are sequentially added. It can be done by

The polymerization initiator used in the second-stage polymerization can be selected from those described in the step (1), and the amount used is not particularly limited,
Usually, it is about 0.0 with respect to 100 parts by weight of the total amount of monomers for forming the acrylic polymer (A-2-1) of the shell.
5 to about 1 part by weight, preferably about 0.1 to about 0.7 part by weight,
More preferably, it can be exemplified within the range of about 0.1 to about 0.5 part by weight. When the reducing agent and the chain transfer agent are used, they can be used in the same proportions as in the case of the core polymer (A-1).

The emulsion polymerization in the second step of step (2) can be carried out at a temperature of generally about 30 to about 100 ° C, preferably about 40 to about 90 ° C.

By the multi-step emulsion polymerization described above, a composite body in which the core portion is made of the carboxyl group-containing acrylic polymer (A-1) and the shell portion is made of the acrylic polymer (A-2-1) An aqueous dispersion of fine particles (A) can be produced.

On the other hand, fine composite particles (A) in the case where the shell polymer (A-2) is a urethane polymer (A-2-2)
Is, for example, a monomer for forming the carboxyl group-containing acrylic polymer of the core described above in the presence of an aqueous solution of urethane polymer or emulsion, preferably urethane polymer emulsion, such as the above-mentioned monomer (M
-1), (M-2) and (M-3) can be added and polymerized.

The urethane polymer emulsion which can be used in this method can be produced, for example, by reacting the above-mentioned urethane prepolymer with a chain extender by a method as described below: a cationic emulsion. As a production method, for example, (1) a urethane prepolymer having an isocyanate group at the terminal may be polymerized using a diol having a tertiary amino group as a chain extender and then cationized with a quaternizing agent or an acid. ,
Alternatively, a method in which a diol having a quaternary amino group is reacted as a chain extender to cationize, and (2) a urethane prepolymer having an isocyanate group at the terminal is polymerized using a polyalkylene polyamine as a chain extender. , A method of reacting epihalohydrin with an acid to cationize, and the like.

As a method for producing an anionic emulsion, for example, (3) a urethane prepolymer having an isocyanate group at the terminal is polymerized with dihydroxycarboxylic acid or diaminocarboxylic acid as a chain extender, and then alkalinized. (4) A urethane prepolymer having an isocyanate group at the terminal obtained from a hydrophobic polyol and an aromatic polyisocyanate is sulfonated and neutralized with a tertiary amine to be anionized. Methods and the like.

Further, as a method for producing a nonionic emulsion, for example, (5) a urethane prepolymer having an isocyanate group at the terminal is dispersed in an aqueous solution containing a diamine and the like using an emulsifier, and water is added. Alternatively, a method of chain extension with a diamine, (6) an alkylene oxide condensate of a long-chain alcohol (a type of nonionic surfactant) and an amine having a hydrophilic group such as a hydroxyl group are added to a urethane prepolymer having an isocyanate group at the end. How to react,
(7) A method in which a urethane prepolymer having an isocyanate group at the terminal is reacted with the above chain extender to form a urethane polymer and mechanically dispersed in water using an emulsifier, and the like can be mentioned.

As the urethane polymer emulsion,
In addition to those described above, for example, a urethane prepolymer is prepared by reacting a polyisocyanate compound or a urethane prepolymer having an isocyanate group at the terminal with a hydroxyl group-containing vinyl monomer such as 2-hydroxyethyl (meth) acrylate. A radical-polymerizable group is introduced therein, and the urethane prepolymer and the (meth) acrylic monomer are emulsified and copolymerized; a part of the isocyanate group of the urethane prepolymer having an isocyanate group at the terminal is variously blocked. Block with a drug,
The urethane prepolymer or urethane-based polymer is reacted with a urethane prepolymer in which a part of the isocyanate group is blocked to obtain the urethane prepolymer or urethane-based polymer containing a blocked isocyanate in the molecule. It is also possible to use a product obtained by emulsifying the above by the same method as described above.

Further, for example, "HUX-350",
"HUX-320", "HUX-232", "HUX-"
401 "," HUX-550 "[above, Asahi Denka Kogyo Co., Ltd.]," Superflex 410 "," Superflex 460 "[above, Dai-ichi Kogyo Seiyaku Co., Ltd.]
Made], "MELUSI-437", "MELUSI-5"
45 ”,“ MELUSI-585 ”,“ MELUSI-
589 "," MELUSI-590 "," MELUSI
-490 "[above, manufactured by Toyo Polymer Co., Ltd.] and other commercially available urethane polymer emulsions can also be used.

Among them, the urethane polymer emulsion is, from the viewpoint of easy formation of fine composite particles and good dispersion stability of the obtained composite particles,
Preference is given to using anionic or nonionic emulsions.

The average particle size of the polymer particles in the urethane polymer emulsion produced as described above is generally 0.01 to 0.5 micron, preferably 0.0.
It is desirable to be in the range of 2 to 0.3 micron.

Polymerization of the monomer for forming the carboxyl group-containing acrylic polymer (A-1) in the core in the presence of the urethane polymer emulsion prepared as described above is carried out by the shell polymer. (A-2) is an acrylic polymer (A
In the case of 2-1), it can be carried out according to the step (1) of the above-mentioned method for preparing the composite fine particles (A), but usually without using a surfactant and / or a protective colloid. .

For example, with respect to the urethane polymer emulsion which is the shell polymer, the acrylic polymer (A-
1) the proportion of monomer (M-1) necessary to form,
It can be carried out by a method of adding (M-2) and (M-3) and performing emulsion polymerization. Further, a shell polymer (A-
As another preparation method of the composite fine particles (A) in the case where 2) is a urethane polymer (A-2-2), for example, the carboxyl group-containing acrylic polymer (A- After forming 1), the acrylic polymer (A-
In the presence of 1), a urethane-based prepolymer having the above radical-polymerizable group (for example, a polyisocyanate compound or a urethane prepolymer to which a radical-polymerizable monomer such as 2-hydroxy (meth) acrylate is added) or urethane. It is also possible to employ a method in which a system polymer is dissolved in an appropriate radical-polymerizable monomer such as an acrylic monomer, and the resulting polymer is polymerized.

As a result, core-shell type composite fine particles (A) having a core composed of a carboxyl group-containing acrylic polymer (A-1) and a shell composed of a urethane polymer (A-2-2). An aqueous dispersion containing is obtained.

The solid content concentration of the resulting aqueous dispersion of the composite fine particles (A) is not particularly limited, and the application,
Although it can be varied over a wide range depending on the ease of handling, it is generally about 10 to about 70% by weight, preferably about 30 to about 65% by weight, more preferably about 40.
A range of from about 60% by weight is suitable.

The aqueous dispersion is usually 2 to 10,
Preferably it can have a pH in the range of 2-8,
Further, about 10 to about 10,000 cps, preferably about 50
~ Viscosity in the range of about 5000 cps (B type rotational viscometer,
25 ° C., with 20 rpm).

The pH of the aqueous dispersion can be adjusted by adding ammonia water, water-soluble amines, an aqueous solution of alkali hydroxide or the like to the aqueous dispersion.

Core-shell type composite fine particles (B) The fine composite particles (B) that can be used in combination with the fine composite particles (A) described above in the aqueous resin dispersion of the present invention are fine composite particles. As with (A), basically,
(1) Glass transition temperature (Tg _B-1 ) is -10 ° C to 50
A core comprising a carboxyl group-containing acrylic polymer (B-1) within the range of ℃, (2) a polymer having a glass transition temperature (Tg _B-2 ) covering the core below -10 ℃ A core-shell type composite fine particle comprising a shell portion (B-2), wherein the core portion occupies 50 to 90% by weight based on the weight of the composite fine particle, and the rest is the shell portion. There is something. However, as the acrylic polymer (B-1) at the core of the composite fine particles (B), its glass transition temperature (Tg
_B-1 ) is lower than the glass transition temperature (Tg _A-1 ) of the acrylic polymer (A-1) at the core of the composite fine particles (A) by at least 10 ° C, preferably 15 ° C or higher. It is different from the composite fine particles (A) in that it is more preferably used at 20 ° C. or lower. Among them, the temperature difference between Tg _A-1 and Tg _B-1 (Tg _A-1 −Tg _B-1 ) is 10 to 5
It is preferably in the range of 0 ° C, especially 15 to 45 ° C, and more particularly 20 to 40 ° C.

Therefore, as the composite fine particles (B),
Among the composite fine particles (A) described above, those satisfying the above glass transition temperature can be selected and used.

Polymer fine particles (C) Polymer fine particles (C) which can be used in combination with the above-mentioned composite fine particles (A) in the aqueous resin dispersion of the present invention.
Has a glass transition temperature (Tg _c ) of −30 ° C. to 50 ° C.
℃, preferably -25 ℃ ~ 40 ℃, more preferably-
The glass transition temperature (Tg _A-1 ) of the acrylic polymer (A-1) at the core of the composite fine particles (A), which is within the range of 20 ° C to 30 ° C, and is at least 10 ° C, preferably There is no particular limitation on the type as long as it is different by 15 ° C. or more, more preferably by 20 ° C. or more (high or low), and it can be used. Among them, the temperature difference between Tg _A-1 and Tg _c | Tg _A-1 −Tg _c | is 10 to 50 ° C., preferably 15 to 45 ° C., more preferably 20 to 40 ° C.
Those within the range are preferred. For example, acrylic polymer, synthetic rubber polymer, saturated fatty acid vinyl polymer,
Various polymers such as urethane polymers and epoxy polymers can be used. Further, as the production method, an appropriate method such as an emulsion polymerization method or a suspension polymerization method can be adopted, but the ease of the polymerization reaction, the stability of the obtained aqueous resin dispersion of the present invention, and the film formed. From the viewpoint of various physical properties, etc., it is preferable to manufacture by an emulsion polymerization method.

For example, in the case of producing fine particles of a polymer such as an acrylic polymer, a synthetic rubber-based polymer and a saturated fatty acid vinyl-based polymer, it is described in the preparation method of emulsion of the composite fine particles (A). Similar to the step (1), by emulsion-polymerizing an appropriate monomer in an aqueous medium in the presence of a surfactant and / or a protective colloid and, if desired, a chain transfer agent, (co) polymerization It is preferably produced as a combined emulsion.

Further, as the urethane polymer fine particles,
When the composite fine particles (A) in which the shell polymer (A-2) is a urethane polymer are prepared, those produced in the same manner as the urethane polymer emulsion described above can be used.

Further, the epoxy polymer fine particles are fine particles containing an epoxy polymer such as bisphenol A type and bisphenol F type as a main component. For example, the epoxy polymer and the composite fine particles (A) described above are used. Method of mixing with a surfactant as described in the preparation method of emulsion and forcibly emulsifying under heating if necessary; introducing a carboxyl group by adding polybasic acid, amino acid, oxyacid, etc. to the epoxy polymer Then, the introduced carboxyl group is neutralized with a volatile base such as ammonia or a lower amine and dispersed in water; an acrylic monomer containing an unsaturated carboxylic acid is polymerized in the presence of an epoxy polymer in an organic solvent. Then, an acrylic polymer containing a carboxyl group is grafted onto the main chain of the epoxy polymer, neutralized with a volatile base, and dispersed in water. Prepared by a method of introducing a carboxyl group by reacting a prepolymerized carboxyl group-containing polymer with an epoxy group of an epoxy polymer in the presence of a tertiary amine, neutralizing with a volatile base and dispersing in water. can do.

The polymer fine particles (C) generally have a content of 0.01
It can have an average particle size in the range of .about.1 micron, preferably 0.01 to 0.5 micron, more preferably 0.02 to 0.3 micron.

Aqueous Resin Dispersion The aqueous resin dispersion of the present invention comprises the above-mentioned composite fine particles (A) and composite fine particles (B) and / or polymer fine particles (C) dispersed in an aqueous medium. By, for example, mixing the aqueous dispersion of the composite fine particles (A) prepared as described above with the aqueous dispersion of the composite fine particles (B) and / or the polymer fine particles (C). be able to.

The mixing ratio of each component at that time can be as follows based on the total amount of the fine particles (A), (B) and (C) (total solid content).

General range Suitable range Optimum range (wt%) (wt%) (wt%) Composite fine particles (A) 30 to 90 40 to 80 50 to 70 Composite fine particles (B) 0 to 70 0 to 60 0 -50 Polymer fine particles (C) 0-70 0-60 0-50 Total amount of fine particles (B) and fine particles 70-10 60-20 50-30 particles (C) Generally, the aqueous resin dispersion of the present invention is Those containing the composite fine particles (A) and the composite fine particles (B) are preferable.

The aqueous resin dispersion provided by the present invention comprises a plurality of core parts mainly composed of a carboxyl group-containing acrylic polymer and a plurality of shell parts mainly covering the core part and mainly composed of an acrylic polymer. Is a composite resin fine particle or an aqueous resin dispersion of a mixture of a plurality of polymer fine particles in which at least one kind of such composite fine particles and polymer fine particles are stably dispersed in an aqueous medium. It can be advantageously used as a vehicle component in various water-based coating compositions such as paints, anti-vibration coatings and caulking materials, especially in vibration-damping water-based coating compositions.

Therefore, the present invention also provides an aqueous coating composition comprising the aqueous resin dispersion of the present invention and an inorganic filler.

The above-mentioned inorganic filler is added to the composition of the present invention for the purpose of increasing the amount of the filler, adjusting the hardness of the coating, preventing the formation of blisters, and the inorganic filler that can be used is substantially the same. Insoluble or sparingly soluble in water, needle-like, fibrous, scale-like, spherical, etc. inorganic solid powder of any shape, for example, calcium carbonate, silica, alumina, kaolin, clay, talc, diatomaceous earth, mica, water Aluminum oxide, glass powder, barium sulfate, magnesium carbonate,
Examples include sepiolite, wollastonite, zeolite and the like.

If necessary, additives such as shirasu balloons, glass balloons, and resin balloons for the purpose of weight reduction or introduction of air bubbles, workability of bentonite, cellulose derivative, etc., viscosity adjustment, etc. were aimed at. Additives can also be used.

The blending amount of these inorganic fillers can be varied within a wide range depending on the type and physical properties desired for the coating composition, and the total solid content of the aqueous resin dispersion is 100. Generally 100 to 39 parts by weight
The amount can be 0 part by weight, preferably 120 to 380 parts by weight, and more preferably 150 to 300 parts by weight.

The above-mentioned inorganic filler is generally used in an amount of about 1 to
It is desirable to have an average particle size in the range of about 50 microns, especially about 5 to about 30 microns.

The aqueous coating composition of the present invention may optionally contain a rust preventive pigment in the same manner as in a conventional coating composition.
Color pigments, crosslinking agents and the like can be contained.

Examples of the above-mentioned rust preventive pigments include red lead; zinc chromate, barium chromate, strontium chromate, and other chromate metal salts; zinc phosphate, calcium phosphate, aluminum phosphate, titanium phosphate, silicon phosphate. ,
Alternatively, metal phosphates such as ortho or condensed phosphates of these metals; molybdenum such as zinc molybdate, calcium molybdate, zinc calcium molybdate, zinc potassium molybdate, zinc potassium phosphomolybdate, and calcium potassium phosphomolybdate. Examples thereof include acid metal salts; metal borate salts such as calcium borate, zinc borate, barium borate, barium metaborate, and calcium metaborate; and the like. Among these rust preventive pigments, non-toxic or low-toxic rust preventive rust pigments such as phosphoric acid metal salts, molybdic acid metal salts, and boric acid metal salts are preferable.

The amount of the rust preventive pigment compounded is, for example, 0 to 5 with respect to 100 parts by weight of the total solid content of the aqueous resin dispersion.
It can be exemplified in the range of 0 parts by weight, preferably 5 to 30 parts by weight.

Examples of the color pigments include organic or inorganic color pigments such as titanium oxide, carbon black, rouge, Hansa yellow, benzidine yellow, phthalocyanine blue, and quinacridone red. The blending amount of these color pigments may be, for example, 0 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the total solid content of the aqueous resin dispersion. .

The particle diameter of these rust preventive pigments and color pigments is preferably in the range of 1 to 50 μm from the viewpoint of the smoothness of the coating film formed of the obtained coating composition.

The aqueous coating composition using the aqueous resin dispersion of the present invention has a total pigment (the above-mentioned inorganic filler, coloring pigment, rust-preventive pigment and weight reduction or introduction of bubbles) in the coating film formed thereby. The total amount of additives for the purpose of) (hereinafter, may be abbreviated as PWC) is preferably 50 to 80% by weight, more preferably 55 to 77% by weight,
More preferably, it should be 60 to 75% by weight. When the PWC value is at least the lower limit value, the strength and chipping resistance of the obtained coating film will be excellent, and when it is at most the upper limit value, the low-temperature impact resistance and flexibility of the obtained coating film will be excellent. Therefore, it is preferable.

(Crosslinking Agent) Further, as a crosslinking agent which can be appropriately added to the aqueous coating composition of the present invention, (a) a water-soluble polyvalent metal salt such as zinc acetate, zinc formate, zinc sulfate, zinc chloride Zinc salts such as; aluminum salts such as aluminum acetate, aluminum nitrate, aluminum sulfate; calcium salts such as calcium acetate, calcium formate, calcium chloride, calcium nitrate, calcium sulfite; barium salts such as barium acetate, barium chloride, barium sulfite; Magnesium salts such as magnesium acetate, magnesium formate, magnesium chloride, magnesium sulfate, magnesium nitrate and magnesium sulfite; lead salts such as lead acetate and lead formate; nickel salts such as nickel acetate, nickel chloride, nickel nitrate and nickel sulfate; Manganese acetate, manganese chloride, manganese sulfate Manganese salts such as manganese nitrate, for example, copper chloride, copper nitrate, copper salts such as copper sulfate; and,
(B) an aziridine compound, for example, a reaction product of the following polyisocyanate crosslinking agent and ethyleneimine such as a reaction product of 4,4'-diphenylmethane diisocyanate and ethyleneimine, (c) a polyisocyanate crosslinking agent, for example , An aromatic polyisocyanate compound, an aliphatic polyisocyanate compound, an alicyclic polyisocyanate compound, and the like, which are used in the production of the urethane-based polymer described above; a dimer or trimer of these polyisocyanate compounds; For example, adducts with polyhydric alcohols used as the chain extenders such as ethylene glycol and trimethylolpropane, (d) water-soluble epoxy resins, such as glycerol diglycidyl ether, and (e) water-soluble melamine Resin, for example Methylol melamine; (f) Water-dispersible blocked isocyanates, such as those obtained by etherifying at least part of the hydroxyl groups of the methylol melamine with methyl alcohol, ethyl alcohol, n-butyl alcohol, etc., for example, trimethylol propane tritolylene diisocyanate methyl ethyl keto. Examples thereof include an adduct of the above-mentioned polyisocyanate crosslinking agent such as oxime adduct and a volatile low-molecular active hydrogen-containing compound.

Examples of the volatile bottom molecule active hydrogen-containing compound include methyl alcohol, ethyl alcohol,
Aliphatic, alicyclic or aromatic alcohols such as n-butyl alcohol, cyclohexyl alcohol, benzyl alcohol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether and phenol; hydroxy tertiary amines such as dimethylaminoethanol and diethylaminoethanol; , Acetoxime, methyl ethyl ketoxime and the like; for example, active methylene compounds such as acetylacetone, acetoacetic acid ester, malonic acid ester and the like; lactams such as ε-caprolactam and the like.

The amount of these cross-linking agents to be used is, for example, from 0 to 100 parts by weight of the polymer fine particles in the composition, from the viewpoint of suppressing the change with time of the viscosity of the obtained coating composition.
A range of 10 parts by weight can be exemplified.

In the aqueous coating composition of the present invention, if necessary, an inorganic dispersant [eg, sodium hexametaphosphate, sodium tripolyphosphate, etc.], an organic dispersant [eg, NOPCOSPERSE 44C (trade name, polycarboxylic acid, etc. Dispersants such as acid type; manufactured by San Nopco Ltd .; defoaming agents such as silicon type; polyvinyl alcohol, cellulose type derivatives, polycarboxylic acid type resins, thickeners and viscosity improving agents such as surfactant type; ethylene Organic solvents such as glycol, butyl cellosolve, butyl carbitol, and butyl carbitol acetate; antiaging agents; preservatives / antifungal agents; ultraviolet absorbers; antistatic agents; and the like can be added and mixed.

The aqueous coating composition of the present invention is generally, but not limited to, about 10 to about 85% by weight,
Preferably about 30 to about 80% by weight, particularly preferably about 5
Contains from 0 to about 70% by weight of solids, and 7
˜11, preferably a pH in the range of 8-10 and a viscosity in the range of about 3,000 to about 100,000 cps, preferably about 5,000 to about 50,000 cps (B-type rotational viscometer, 25 ° C., with 20 rpm).

The base material to which the aqueous coating composition of the present invention can be applied is not particularly limited, and examples thereof include steel sheets; for example, lead-tin alloy plated steel sheets (tan sheet steel sheets), tin plated steel sheets, and aluminum plated steel sheets. , Various plated steel plates such as lead plated steel plate, chrome plated steel plate and nickel plated steel plate; coated steel plate such as electrodeposition coated steel plate; and the like.

The aqueous coating composition of the present invention can be coated by a coating method known per se, for example, brush coating, spray coating,
It can be performed by roller coating or the like, but airless spray coating is generally preferable.

The coating film thickness at that time varies depending on the use of the base material and the like, but is usually about 500 μm or more, especially about 10 μm.
A range of 0 to about 5000 microns is suitable. The coating film can be dried by natural drying, heat drying or the like.

[0121]

EXAMPLES The present invention will be described in more detail below with reference to examples. In addition, various physical properties in this specification are measured by the following methods.

Glass transition temperature (Tg) : Thickness about 0.05
mm aluminum foil, inner diameter about 5 mm, depth about 5 m
In a cylindrical cell of m, a sample of an aqueous dispersion of polymer of about 10
What was weighed out and dried at 100 ° C. for 2 hours was used as a measurement sample. Differential scanning calorimeter [Differential Scanning Ca
lorimeter: SSC-500 manufactured by Seiko Instruments Inc.
0 type], the temperature rising rate from -150 ° C to 10 ° C / min
Measure and decide with.

According to the above-mentioned Tg measuring method, in the case of the multi-layered particle having the core and the shell such as the fine particles of the acrylic polymer composite contained in the aqueous resin dispersion of the present invention, two different Tg values are obtained. Since it can be measured, the higher Tg value is Tg _A-1
Or Tg _B-1 , and the lower Tg value is Tg _A-2 or Tg _B-2 .

Viscosity : 25 ° C., 20 with a B type rotary viscometer
Measure under the conditions of rpm.

Carboxyl group content : About 10 g of an aqueous polymer dispersion was precisely weighed, diluted with about 300 g of deionized water, treated with an ion exchange resin and adjusted to pH 3 or less to prepare a sample. In the case of the composite fine particles having a shell made of a urethane polymer, a carboxyl group is added to the aqueous dispersion before treatment with an ion exchange resin in order to prevent occurrence of aggregation of the aqueous dispersion. It is preferable to add a surfactant or the like which is not included. This sample was titrated with a 0.5 N aqueous sodium hydroxide solution using a self-recording automatic conductivity titrator, and the carboxyl group content per 100 g of the polymer was calculated.

Average particle size : The polymer aqueous dispersion was diluted 50,000 to 150,000 times with distilled water, and sufficiently stirred and mixed.
About 1 using a Pasteur pipette in a mmφ glass cell
0 ml was collected, and this was used as a dynamic light scattering photometer DLS-700.
It is set at a predetermined position of [Otsuka Electronics Co., Ltd.] and measured under the following measurement conditions.

Measurement conditions Measurement temperature 25 ± 1 ° C. Clock rate 10 μsec Correlation channel (Corel.Channel) 512 Total number of measurements 200 times Light scattering angle 90 ° The average particle size is calculated by computer processing the above measurement results. .

The preparation and test methods of test samples used in the following examples and comparative examples are as follows.

(1) Preparation of test piece An automobile steel sheet specified in JIS G-3141 was electro-deposited with a cationic electro-deposition paint "U-600" manufactured by Nippon Paint Co., Ltd. 0.8 × 100 × A 200 mm steel plate (ED steel plate) is coated with each of the aqueous coating composition samples by an airless spray coating method so that the dry coating film has a thickness of 500 μm, and dried at room temperature.

(2) Adhesion test Using the test piece prepared in the above (1), a base material tester [manufactured by Suga Tester Co., Ltd.] was used to form a base material at intervals of 2 mm in both length and width from the coated surface. 4 with a cutting line reaching the depth
Make 100 goggles in cm ² . 24mm width cellophane tape [Nichiban Co., Ltd.]
[Production] is affixed, and the film is rapidly peeled by 180 °, and the number of eyes remaining in the coating film is counted and displayed as the number of remaining coating film eyes / 100.

(3) Chipping resistance test The test piece prepared in the previous section (1) was allowed to stand for 3 hours under a constant temperature condition of about 25 ° C., and then the same goggles tester used in the previous section (2) was used. Using the cutting surface, 11 cutting wires are placed at intervals of 2 mm in the vertical direction and 6 cutting wires are placed at intervals of 4 mm in the horizontal direction at a depth reaching the substrate, and measurement is performed at the same temperature.

The test piece was stood upright at an angle of 60 ° with respect to the horizontal plane and fixed, and a nut (M-4) was vertically attached to the coated surface from a height of 2 m using a polyvinyl chloride pipe of 25 mmφ. Aiming at the cut part, continuously dropping it, E
The evaluation is made by the total weight of the nuts that dropped when the base material of the D steel plate was exposed.

(4) Low temperature impact resistance test The test piece prepared in the item (1) before was left under the constant temperature condition of -30 ° C for 3 hours or more, and then JIS K-540 at the same temperature.
Perform a DuPont type impact resistance test according to 0.

The condition at this time is that the radius of the tester is 6.35 ±
Attach a 0.33mm shooting die and a pedestal, sandwich the test piece with the coating surface facing upwards, drop a weight of 500 ± 1g from the height of 50cm onto the shooting die, and damage the coating surface. The degree of is visually evaluated according to the following evaluation criteria.

◎ ・ ・ ・ ・ ・ No change at all ○ ・ ・ ・ Slightly small cracks occurred △ ・ ・ ・ Many small cracks occurred × ・ ・ ・ Large cracks occurred (5) Before vibration control test In item (1), instead of the ED steel plate, a beam (metal plate for measurement sample preparation attached to the damping material property evaluation system)
A test piece prepared in the same manner as above except that the dry film thickness is 2000 μm is prepared according to ASTM E756.
According to -83, loss coefficient [loss] at each temperature of 0 ° C, 20 ° C, 40 ° C and 60 ° C using a damping material characteristic evaluation system “DAMP TEST” [manufactured by Toyo Corporation]・ Factor (Loss Facto
r)] was measured. The measurement is performed by the 3 dB method,
The obtained data is converted to a frequency of 140 Hz.

Preparation of Aqueous Dispersion of Composite Fine Particles Reference Example 1 In a reaction vessel equipped with a stirrer, reflux condenser thermometer and raw material addition device, 94 parts by weight of deionized water and sodium dodecylbenzenesulfonate as a surfactant. 1 part by weight and 1 part by weight of polyoxyethylene nonylphenol ether (HLB about 16) were charged, and the temperature was raised to 70 ° C. while flowing nitrogen. Then, methyl methacrylate (MMA) 35.2 as a core-forming monomer (M _c ) was placed in the reaction vessel.
Parts by weight, 2-ethylhexyl acrylate (EHA) 2
7.2 parts by weight, 16 parts by weight of styrene (St) and 1.6 parts by weight of acrylic acid (AA) are uniformly mixed, and a 5% by weight aqueous solution of ammonium persulfate (APS) as an aqueous solution of a polymerization initiator. 6 parts by weight were continuously added over 3 hours, and then the mixture was kept at the same temperature for 1 hour to obtain emulsion containing an acrylic polymer for forming a core.
A part of this emulsion was taken out, and the carboxyl group content of the core polymer was measured by the conductivity titration method.

Subsequently, while maintaining the temperature at 70 ° C., a monomer mixture solution in which 15.6 parts by weight of EHA and 4.4 parts by weight of StA were uniformly mixed as a shell-forming monomer (M _s ) with the acrylic polymer emulsion, 2 parts by weight of a 5% by weight aqueous solution of APS were continuously added over 1 hour,
Thereafter, the mixture was kept at the same temperature for 2 hours, and then an appropriate amount of about 25% by weight of ammonia water was added to obtain an aqueous dispersion containing fine particles of acrylic polymer composite particles.

Compositions of M _c and M _{s in} this polymerization, Tg of core polymer and Tg of shell polymer,
Further, the weight ratio of the core portion and the shell portion is shown in Table 1 below, and the solid content, pH, viscosity, average particle diameter, carboxyl group content of the core polymer and the composite fine particles of the obtained aqueous dispersion are shown in Table 1 below. 2 shows.

Reference Examples 2 to 5 In Reference Example 1, the composition of the monomer mixture M _c was changed,
Reference Example 1 except that the Tg of the core polymer was changed as necessary.
In the same manner as described above, an aqueous dispersion containing fine particles of an acrylic polymer composite was obtained. M _c and M _s during these polymerizations
The respective compositions, the Tg of the core polymer and the Tg of the shell polymer, and the weight ratio of the core and the shell are shown in Table 1 below. The solid content, pH, viscosity, and average of the obtained aqueous dispersion are shown in Table 1 below. Particle size,
The carboxyl group contents of the core polymer and the fine composite particles are shown in Table 2 below.

Reference Example 6 An aqueous dispersion comprising fine particles of an acrylic polymer in the same manner as in Reference Example 3 except that the composition of the monomer mixture M _s was changed to change the Tg of the shell polymer. A liquid was obtained. The respective compositions of M _c and M _s during this polymerization, Tg of the core polymer and Tg of the shell polymer, and the weight ratio of the core and the shell are shown in Table 1 below. The solid content, pH, viscosity, average particle diameter, carboxyl group content of the core polymer and composite fine particles are shown in Table 2 below.

Reference Example 7 An acrylic-based polymer was prepared in the same manner as in Example 1 except that the composition and the amount of the monomer mixed liquids M _c and M _s were changed and the ratio of the core and the shell was changed. An aqueous dispersion composed of coalesced composite fine particles was obtained. M _c during polymerization of these
And the composition of M _s , Tg of the core polymer and Tg of the shell polymer, and the weight ratio of the core and the shell are shown in Table 1 below, in which the solid content of the obtained aqueous dispersion, pH, The viscosity, the average particle diameter, the carboxyl group content of the core polymer and the composite particles are shown in Table 2 below.

Reference Example 8 In a reaction vessel similar to that used in Reference Example 1, urethane polymer emulsion "HUX-350" [Asahi Denka Kogyo Co., Ltd., solid content 30% by weight; 3]] 100 parts by weight and 22 parts by weight of deionized water are charged,
The temperature was raised to 70 ° C. while flowing nitrogen. Next, as the monomer (M _c ) for forming the core part, 15.4 parts by weight of MMA, 39.2 parts by weight of EHA, 14 parts by weight of St and AA1.
4 parts by weight of the monomer mixture was uniformly added, and 8 parts by weight of a 5% by weight aqueous solution of APS as an aqueous solution of a polymerization initiator were continuously added for 3 hours, and then the mixture was kept at the same temperature for 1 hour, and then about 25 An appropriate amount of wt% ammonia water was added to obtain an aqueous dispersion of fine composite particles having an acrylic copolymer as the core and a urethane polymer as the shell.

The composition of M _{c in} this polymerization, the type of urethane polymer emulsion used for the shell, the Tg of the core polymer and the Tg of the shell polymer, and the weight ratio of the core to the shell were determined. Table 1 below shows the solid content, pH, viscosity, average particle size, and carboxyl group content of the core polymer and composite fine particles of the obtained aqueous dispersion.

[0144]

[Table 1]

[0145]

[Table 2]

Preparation of Aqueous Dispersion of Polymer Fine Particles Reference Example 9 In a reaction vessel similar to that used in Reference Example 1, deionized water 8 was added.
9.5 parts by weight, 1.25 parts by weight of sodium dodecylbenzene sulfonate as a surfactant and 1.25 parts of polyoxyethylene nonylphenol ether (HLB about 16).
Part by weight was charged and the temperature was raised to 70 ° C. while flowing nitrogen. Then, as a monomer for forming polymer fine particles in the reaction vessel, 44 parts by weight of MMA, 34 parts by weight of EHA, 20 parts by weight of St and 2 parts by weight of AA are mixed uniformly, and a polymerization initiator solution AP is used.
10 parts by weight of a 5% by weight aqueous solution of S was continuously added over 3 hours, and then the mixture was kept at the same temperature for 1 hour, then about 25
A proper amount of wt% ammonia water was added to obtain an aqueous dispersion of acrylic polymer particles.

Table 3 shows the monomer composition in this polymerization, the Tg of the obtained polymer fine particles, and the solid content, pH, viscosity and average particle diameter of the aqueous dispersion of the obtained polymer fine particles.

Reference Examples 10 and 11 In the same manner as in Reference Example 9 except that the use ratio of the monomers MMA and EHA was changed to change the Tg of the polymer, the aqueous solution of acrylic polymer particles was prepared. A dispersion was obtained.
Monomer composition used, T of the obtained polymer fine particles
g, and the solid content of the resulting dispersion of polymer particles,
Table 3 shows pH, viscosity and average particle size.

Reference Example 12 In a reaction vessel similar to that used in Reference Example 1, deionized water 41 was added.
"Goselan L-326" as parts by weight and as protective colloid
6 "[manufactured by Nippon Synthetic Chemical Industry Co., Ltd., modified polyvinyl alcohol] 2 parts by weight were charged, and the temperature was kept at 80 ° C while flowing nitrogen.
The temperature was raised to. Next, in this reaction vessel, 46.6 parts by weight of deionized water prepared in another vessel, 2 parts by weight of sodium dodecylbenzenesulfonate as a surfactant, and 100 parts by weight of vinyl acetate (VAc) were added as a pre-emulsion and a polymerization initiator. 6 parts by weight of an aqueous solution of 5% by weight of APS as an aqueous solution was continuously added for 3 hours, and then the mixture was kept at the same temperature for 1 hour, and then an appropriate amount of about 25% ammonia water was added thereto to obtain vinyl acetate polymer fine particles. An aqueous dispersion was obtained.

Table 3 shows the monomer composition in this polymerization, the Tg of the obtained polymer fine particles, and the solid content, pH, viscosity and average particle diameter of the aqueous dispersion of the obtained polymer fine particles.

An aqueous dispersion of a urethane polymer used as the shell polymer of Reference Example 8 and used as polymer fine particles in Examples 12 to 14 described later is shown in Table 4.
Shown in.

[0152]

[Table 3]

[0153]

[Table 4]

[0154] Aqueous dispersions 100 parts by weight of the composite particles of Example 1 acrylic polymer prepared in Reference Example 1 as a composite fine particles (A) of the aqueous coating composition (about 50 parts by weight solids) And fine particles of composite (B)
As 100 parts by weight of the aqueous dispersion of the fine particles of the acrylic polymer composite prepared in Reference Example 4 (50 parts by weight as solid content)
To 200 parts by weight of the aqueous resin dispersion liquid (100 parts by weight of solid content) obtained by using
4C "[manufactured by San Nopco Ltd., polycarboxylic acid type dispersant] 2.0 parts by weight (solid content: about 0.88 parts by weight), powdered calcium carbonate 218 parts by weight as an inorganic filler, carbon black 3 parts by weight as a color pigment. Parts and 12 parts by weight of barium metaborate as a rust preventive pigment are uniformly dispersed using a disper, and then as a thickener, “Adecan UH
-472 "[manufactured by Asahi Denka Kogyo Co., Ltd.] and added with 0.5 part by weight, and further stirred to give a PWC of 70% by weight and a solid content of 7%.
A 6.6 wt% aqueous coating composition was prepared.

Various physical property tests were conducted using the obtained aqueous coating composition. Table 5 shows the blending composition, properties, and measurement results of various physical properties of the coating composition.

Example 2 and Comparative Examples 1 and 2 In Example 1, the composite fine particles (A) were used as Reference Example 1.
Aqueous dispersion of composite fine particles and composite fine particles (B)
As Example 1 except that, instead of using 100 parts by weight of each of the aqueous dispersions of the composite fine particles of Reference Example 4, the use ratio was changed or the aqueous dispersion of the composite fine particles of Reference Example 4 was not used. Similarly, an aqueous coating composition was prepared and various physical property tests were conducted. Table 5 shows the blending composition, properties, and measurement results of various physical properties of the coating composition.

Example 3 and Comparative Examples 3 to 4 In Example 1, the composite fine particles (B) were used as Reference Example 4.
In the same manner as in Example 1 except that the aqueous dispersion of the composite fine particles prepared in Reference Example 2, Reference Example 6 or Reference Example 8 was used instead of using 100 parts by weight of the aqueous dispersion of the composite fine particles. An aqueous coating composition was prepared and various physical properties were tested. Table 5 shows the blended composition, properties, and measurement results of various physical properties of the coating composition.

Examples 4 to 6 and Comparative Examples 5 to 6 Refer to Example 1 as the composite fine particles (A) in Example 1.
Example 1 except that the aqueous dispersion of the composite fine particles prepared in Reference Example 2, Reference Example 3, Reference Example 5, Reference Example 6 or Reference Example 7 was used instead of using the aqueous dispersion of the composite fine particles in Example 1 respectively. An aqueous coating composition was prepared in the same manner as above, and various physical property tests were conducted. Table 5 shows the blended composition, properties, and measurement results of various physical properties of the coating composition.

The aqueous coating composition of Comparative Example 5 using the aqueous dispersion of the composite fine particles of Reference Example 5 had poor dispersibility of the inorganic filler and the like when the composition was blended, and the obtained aqueous solution was obtained. The coating composition had insufficient stability and was not suitable for airless spray coating.

[0160]

[Table 5]

Example 7 In Example 1, reference example 4 was used as the composite fine particles (B).
The same procedure as in Example 1 was repeated except that the aqueous dispersion of polymer fine particles prepared in Reference Example 11 was used as the polymer fine particles (C) instead of using 100 parts by weight of the aqueous dispersion of composite fine particles. Various compositions were prepared and various physical properties were tested. Table 6 shows the blended composition, properties and measurement results of various physical properties of the coating composition.

Examples 8 and 9 In Example 7, reference example 1 was used as the composite fine particles (A).
In place of using 100 parts by weight of the aqueous dispersion of the composite fine particles of, the aqueous coating composition was prepared in the same manner except that the aqueous dispersion of the composite fine particles of Reference Example 3 or 7 was used, and various physical properties tests were conducted. I went. Table 6 shows the blended composition, properties, and measurement results of various tests of the coating composition.

Example 10 and Comparative Example 7 In Example 7, the composite fine particles (A) were used as Reference Example 1.
Aqueous dispersion of composite fine particles and polymer fine particles (C)
Instead of using 100 parts by weight of each of the aqueous dispersions of polymer fine particles of Reference Example 11, the aqueous dispersion of the composite fine particles prepared in Reference Example 4 and the aqueous dispersion of the polymer fine particles prepared in Reference Example 9 are respectively used. An aqueous coating composition was prepared in the same manner as in Example 7 except that 100 parts by weight was used, or the proportions used were changed, and various physical properties were tested.
Table 6 shows the blended composition, properties, and measurement results of various tests of the coating composition.

Example 11 and Comparative Example 8 In Example 10, instead of using 100 parts by weight of the aqueous dispersion of the polymer particles of Reference Example 9 as the polymer particles (C), the polymer particles prepared in Reference Example 10 were used. An aqueous coating composition was prepared and various tests were carried out in the same manner as in Example 10 except that 100 parts by weight of each of the aqueous dispersion of 1. or the aqueous dispersion of polymer fine particles prepared in Reference Example 11 was used. Table 6 shows the blended composition, properties, and measurement results of various tests of the coating composition.

Example 12 In Example 10, 1 aqueous solution of the composite fine particles of Reference Example 4 was used as the composite fine particles (A) and 1 aqueous polymer dispersion of Reference Example 9 was used as the polymer fine particles (C).
Instead of using 00 parts by weight, 140 parts by weight of the aqueous dispersion of the composite fine particles of Reference Example 4 (70 parts by weight in solid content) and 60 parts by weight of the aqueous dispersion of the fine particles of vinyl acetate polymer prepared in Reference Example 12 were used. An aqueous coating composition was prepared and various tests were carried out in the same manner as in Example 10 except that (30 parts by weight of solid content) was used. Table 6 shows the blended composition, properties, and measurement results of various tests of the coating composition.

Examples 13 to 15 In Example 12, instead of using 60 parts by weight (30 parts by weight of solid content) of the aqueous dispersion of vinyl acetate polymer particles of Reference Example 12 as the polymer particles (C), urethane was used. Aqueous Dispersion of Fine Polymer Particles “HUX-232”, “HU
X-350 "[above, Asahi Denka Kogyo KK, urethane polymer emulsion, solid content 30% by weight] 100 parts by weight (solid content about 30 parts by weight), or" HUX-320 ".
[Asahi Denka Kogyo Co., Ltd., urethane polymer emulsion, solid content 33% by weight] 91 parts by weight (solid content about 30%
An aqueous coating composition was prepared in the same manner as in Example 12 except that (part by weight) was used, and various physical property tests were conducted. Table 6 shows the blended composition, properties, and measurement results of various tests of the coating composition.

Comparative Example 9 In Example 7, the composite fine particles (A) were used as Reference Example 1.
An aqueous coating composition was prepared in the same manner as in Example 7, except that the aqueous dispersion of polymer fine particles prepared in Reference Example 9 was used instead of using 100 parts by weight of the aqueous dispersion of composite fine particles. Various physical property tests were conducted. Table 6 shows the blended composition, properties, and measurement results of various tests of the coating composition.

[0168]

[Table 6]

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-41492 (JP, A) JP-A-5-148446 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08L 1/00-101/16 C09D 101/00-201/10

Claims (24)

(57) [Claims] 1. An aqueous resin dispersion liquid containing polymer fine particles dispersed in an aqueous medium, wherein the polymer fine particles have (A) a glass transition temperature (Tg _A-1 ) of −10 ° C. or higher. 5
A core comprising a carboxyl group-containing acrylic polymer (A-1) in the range of 0 ° C, and a polymer (Ag) having a glass transition temperature (Tg _A-2 ) lower than -10 ° C for coating the core (A). −
2) A core-shell type composite fine particle comprising a shell portion comprising 2), wherein the core portion is 50% based on the weight of the composite fine particle.
To (B) glass transition temperature (Tg _B-1 ) of -10 ° C.
_A carboxyl group-containing acrylic polymer (50 ° C.) at least 10 ° C. lower than the glass transition temperature (Tg _A-1 ) of the polymer (A-1) at the core of the composite fine particles (A) ( A core-shell type composite body comprising a core part made of B-1) and a shell part made of a polymer (B-2) having a glass transition temperature (Tg _B-2 ) lower than -10 ° C for covering the core part. Fine particles, the core of which is 5 based on the weight of the fine composite particles
Composite fine particles occupying 0 to 90 parts by weight and the rest being shells and / or (C) having a glass transition temperature (Tg _c ) of -3.
It is in the range of 0 ° C to 50 ° C and the glass transition temperature (T of the polymer (A-1) at the core of the composite fine particles (A) (T
g _{A- 1} ) and polymer fine particles different from each other by at least 10 ° C., based on the total amount of the fine particles (A), (B) and (C), 30 to 90% by weight of the composite fine particles (A), And the total amount of the composite fine particles (B) and the polymer fine particles (C) is 70
An aqueous resin dispersion containing 10 to 10% by weight. 2. The glass transition temperature (Tg _A-1 ) of the acrylic polymer (A-1) at the core of the fine composite particles (A) and the acrylic polymer (Tg _A-1 ) at the core of the fine composite particles (B) ( B-1)
Glass transition temperature (Tg _B-1 ) of -5 ℃ ~ 45
The aqueous resin dispersion according to claim 1, which is in the range of ° C. 3. The polymer (A) in the shell portion of the composite fine particles (A).
-2) glass transition temperature (Tg _A-2 ) and the glass transition temperature (T) of the polymer (B-2) at the shell of the composite fine particles (B).
The aqueous resin dispersion liquid according to claim 1, wherein g _B-2 ) is in the range of -15 ° C to 60 ° C, respectively. 4. The acrylic polymer at the core of the fine composite particles (A) has a glass transition temperature (Tg _B-1 ) of the acrylic polymer (B-1) at the core of the fine composite particles (B). (A-1)
The aqueous resin composition according to claim 1, which is lower than the glass transition temperature (Tg _A-1 ) thereof by 15 ° C or more. 5. The glass transition temperature (Tg _A-1 ) of the acrylic polymer (A-1) at the core of the fine composite particles (A) and the acrylic polymer (Tg _A-1 ) at the core of the fine composite particles (B) ( B-1) glass transition temperature (Tg _B-1 ) difference (Tg _A-1 -T
The aqueous resin dispersion according to claim 1, wherein g _B-1 ) is in the range of 10 to 50 ° C. 6. The glass transition temperature (Tg _c ) of the polymer fine particles (C) is in the range of −25 ° C. to 40 ° C.
The aqueous resin dispersion described in 1. 7. The acrylic polymer of the core portion of the glass transition temperature of the polymer fine particles (C) (Tg _c) composite fine particles (A) and (A-1) Glass transition temperature (Tg _A-1) 15 ° C
The aqueous resin composition according to claim 1, which is different from the above. 8. The glass transition temperature (Tg _A-1 ) of the acrylic polymer (A-1) at the core of the composite fine particles (A) and the glass transition temperature (Tg _c ) of the polymer fine particles (C). The aqueous resin dispersion according to claim 1, wherein the temperature difference is in the range of 10 to 50 ° C. 9. A carboxyl group-containing acrylic polymer (A-1) and (B-1) are each a polymer (A-1).
And (B-1) the aqueous resin dispersion according to claim 1, which contains 2.5 to 100 milligram equivalents of carboxyl groups per 100 g. 10. In the composite fine particles (A) and (B), the core portion is 60 based on the weight of the composite fine particles.
The aqueous resin dispersion according to claim 1, which accounts for about 85% by weight. 11. A carboxyl group-containing acrylic polymer (A-1) and (B-1) are each represented by the formula (M-1): Wherein R ¹ represents a hydrogen atom or a methyl group, and R ²
Represents a linear or branched alkyl group having 1 to 12 carbon atoms, represented by: (meth) acrylic acid alkyl ester 40 to 99.5% by weight, (M-2) C 3 to 5 carbon atoms
Α, β-unsaturated mono- or di-carboxylic acid of 0.5 to 20
% By weight, and (M-3) formula: In the formula, R ³ represents a hydrogen atom or a methyl group, and X represents a hydrogen atom, a methyl group, an ethyl group, a vinyl group, a mono-
Alternatively, it represents a di-halovinyl group, an aryl group having 6 to 8 carbon atoms, a nitrile group or an —OCOR ⁴ group, wherein:
R ⁴ represents a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, and is represented by the above (M-1)
The aqueous resin dispersion according to claim 1, which is a carboxyl group-containing acrylic copolymer obtained by copolymerization of 0 to 59.5% by weight of a monomer copolymerizable with the (meth) acrylic acid alkyl ester. . 12. The aqueous resin dispersion according to claim 1, wherein the polymers (A-2) and (B-2) are an acrylic polymer or a urethane polymer, respectively. 13. The acrylic polymer has the formula (M-1): Wherein R ¹ represents a hydrogen atom or a methyl group, and R ²
Represents a straight-chain or branched-chain alkyl group having 1 to 12 carbon atoms.
To 100% by weight, (M-2) C3 to C5 α, β-
0-10% by weight of unsaturated mono- or di-carboxylic acid, and (M-3) formula: In the formula, R ³ represents a hydrogen atom or a methyl group, and X represents a hydrogen atom, a methyl group, an ethyl group, a vinyl group, a mono-
Alternatively, it represents a di-halovinyl group, an aryl group having 6 to 8 carbon atoms, a nitrile group or an —OCOR ⁴ group, wherein:
R ⁴ represents a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, and is represented by the above (M-1)
The aqueous resin dispersion according to claim 12, which is an acrylic (co) polymer obtained by (co) polymerization of 0 to 50% by weight of a monomer copolymerizable with the (meth) acrylic acid alkyl ester. 14. The aqueous resin dispersion liquid according to claim 1, wherein the composite fine particles (A) and (B) each have an average particle diameter within the range of 0.05 to 5 microns. 15. The aqueous resin dispersion liquid according to claim 1, wherein each of the composite fine particles (A) and (B) contains a carboxyl group in an amount of 5 to 150 mg per 100 g of the particles. 16. The aqueous solution according to claim 1, wherein the polymer fine particles (C) are fine particles of an acrylic polymer, a synthetic rubber polymer, a saturated fatty acid vinyl polymer, a urethane polymer or an epoxy polymer. Resin dispersion. 17. The aqueous resin dispersion according to claim 1, wherein the polymer fine particles (C) have an average particle diameter within the range of 0.01 to 1 micron. 18. 40 to 80% by weight of the composite fine particles (A), and the composite fine particles (B) and the polymer fine particles (based on the total amount of the fine particles (A), (B) and (C). The aqueous resin dispersion according to claim 1, which contains 60 to 20% by weight in total of C). 19. An aqueous coating composition comprising the aqueous resin dispersion according to claim 1 and an inorganic filler. 20. The inorganic filler is calcium carbonate, silica, alumina, kaolin, clay, talc, diatomaceous earth, mica, aluminum hydroxide, glass powder, barium sulfate,
20. The composition of claim 19 selected from the group consisting of magnesium carbonate, sepiolite, wollastonite and zeolites. 21. The composition according to claim 19, which contains an inorganic filler in an amount of 100 to 390 parts by weight based on 100 parts by weight of the total solid content of the aqueous resin dispersion liquid. 22. The composition of claim 19, wherein the mineral filler has an average particle size in the range of 1-50 microns. 23. The composition according to claim 19, wherein the aqueous coating composition is a vibration damping aqueous coating composition. 24. An article coated with the composition of claim 23.